Longevity is long life or existence. Reflections on longevity have usually gone beyond acknowledging the basic shortness of human life and included thinking about, and conceiving, methods to extend life (indefinitely). Longevity has been a topic not only for the scientific community but also for writers of science fiction and utopian novels.

Different people have different lifestyles. But it appears that it matters most where in the world (rather than how) you live. Health care and hygiene seem to influence life expectancy more than any other factor (from the CIA World Fact Book):

First World: 77-81 years

Second World: 65-77 years

Third World: 35-60 years

Even habits such as smoking do not seem to have a major influence: Japan, a country with lots of tobacco consumption, has the highest life expectancy in the world (80.91 years, CIA Fact Book 2002). Hong Kong, a dense 7 million people city with constant stress, follows Japan closely (79.8 years, CIA Fact Book 2002).

Food and lifestyle make rather a small difference (all from
CIA World Fact Book 2002):